1. Technical Field
The present disclosure relates generally to devices for transdermal fluid delivery of medicaments. More particularly, the present disclosure relates to micro-needle array patches for transdermal fluid delivery of drugs and/or nutrients.
2. Background of the Related Art
Transdermal fluid delivery of drugs is an effective and convenient way for patients to receive medications and/or nutrients. Transdermal fluid delivery of drugs is particularly useful where a patient needs to maintain a continuous level of medication in the blood stream over an extended period of time, where the patient is likely to forget to take medication or has difficulty taking medication orally, and/or where the patient is unable to properly absorb the medications or nutrients through the digestive system. However, not all drugs and nutrients are easily absorbed through the epidermis. For example, the molecules of the drugs or nutrients may be too large, the drugs or nutrients may be too lipophobic, and/or the required dose may be too large to be efficiently absorbed by the epidermis.
More recently, transdermal patches including micro-needle arrays have been used to puncture the epidermal layer to deliver drugs and/or nutrients into the blood stream, circumventing some of the limitations associated with absorbing the drugs and/or nutrients through the epidermis. However, when these micro-needle arrays are removed from the patient's epidermis, the punctures created by the needles, if not properly protected, provide a potential avenue for the introduction of virus and bacteria into the blood stream. Additionally, if the needles are not properly maintained prior to insertion, virus and/or bacteria on the needles themselves may infect the patient upon insertion of the micro-needle array.
For example, U.S. Pat. No. 7,226,439 discloses a microneedle drug delivery device including a reservoir and a substrate having one or more microneedles attached thereto and extending therefrom. The reservoir is selectably connectable to the substrate such that the reservoir contents can flow from the reservoir out through the tips of the microneedles. In use, the microneedles are inserted into the skin, while the substrate is retained in position on the skin by an adhesive. The reservoir may then be connected to the substrate for delivering the drugs to the patient. At the completion of treatment, the substrate is removed from the patient's skin, leaving behind a plurality of open puncture wounds where the microneedles were inserted. These unprotected, open puncture wounds are susceptible to disease and/or infection. Further, there is the risk that the exposed microneedles may become contaminated prior to insertion into the patient's skin, putting the patient at risk of disease and/or infection.